Improved sliding electrical brush performance through the use of water lubrication

Electrical and wear performances of sliding electrical currents are critically dependent on the local contact spot temperature resulting from Joule and frictional heating. A method of water application for both lubricating and cooling significantly decreases wear rates. Increases in the useable current densities in continuous operation are achieved with metal fiber brushes. Brush polarity has a distinct effect on the brush characteristics, with the negative brush-positive rotor couple displaying much lower wear rates (by a factor of about 7) and slightly higher average voltage drops. When adequate moisture is provided, metal fiber brushes perform well consistently. Inadequate moisture results in periods of apparently excellent brush performance followed by high wear rates and often by destruction of the brushes.<>